(a) Field of the Invention
The present invention relates to a DC converter circuit, in particular to a simplified multilevel DC converter circuit structure comprising six power switches.
(b) Description of the Related Art
With reference to FIG. 15 for a conventional DC converter circuit, the DC converter circuit includes eight power switches Sa1, Sa2, Sa3, Sa4, Sb1, Sb2, Sb3, Sb4, wherein different switching combinations of the power switches are controlled to achieve the effect of converting a DC voltage to an AC voltage for the output.
However, the foregoing conventional DC converter circuit adopts eight power switches Sa1, Sa2, Sa3, Sa4, Sb1, Sb2, Sb3, Sb4, not only involving too many components, but also failing to lower the component cost effectively, since every power switch has to bear a withstand voltage equal to the supply voltage. Furthermore, all power switches perform the switching operation at a high frequency when the conventional DC converter circuit converts direct currents, and thus incurring a higher switching loss and an easier damage to the power switches.